and I moved the UAS to that tank because I needed a cured screen ASAP to keep ammonia under control after the move. So I fired up an L2 waterfall on my 120 around the same time. This Rev 1 L2 is a "second", meaning I erred on the acrylic box which forced me to have to shave off part of the heat sink to make it fit. I then modded the LED array so that it had the 2x half-power blues on each side, still all Satis LED. When I get around to putting both scrubbers back on the tank, I will replace all LEDs with Philips Luxeons so that everything starts over on an even playing field.

The 120,as a result of having no filtration for a few weeks, has had a nutrient spike. N and P were both already pretty high, but jumped up really fast after pulling the UAS and installing the waterfall L2 with a

The waterfall unit went online on 2/21/13 and the first cleaning was done on 3/6/13 at 13 days. I took a video of that growth on 3/5 but it is a huge file and will need to be uploaded later.

Here are the videos that I took last night of the cleaning process. This is growth from 3/6/13 to 3/13/13 - 7 days growth on a high nutrient tank.

I thought that I had recorded the first cleaning (at 13 days) and lo and behold, I found it. So this is growth from a bare screen to 13 days on a high nutrient tank. High nutrient meaning that the water tested at Nitrate over 40ppm, and Phosphate over 0.5.

Cleaned both the 120 and 40 screens today. Harvest on the UAS was about the same as it was last time - a healthy 81g. The harvest on the 120 was not even worth weighing, it was easily 1/4 of that.

The surprising results:

120: N=20-30 still, P=0.11. Within the +/- error, but at worst, holding.

40: N=80 ish still, P=0.93.

easily four times the biomass, and still the parameters are worse. So growing algae for the sake of growing algae is not effective. Growing algae that actually filters is the goal. I get thick green volumous growth on the UAS, but it doesn't do diddly squat.

Looks like I forgot to mirror-update this thread from the one on algae scrubbers...oops!

This was posted on July 2nd

----------------

Update on the UAS. I had a VERY interesting and telling development happen. To recap from the last harvest, I had take vids and pics but hadn't had time to post.

So here is the harvest on June 1st (same day as the harvest discussed in post #10)

IIRC, in the second pic, the pile on the right is from the box, the left is from the screen.

Then on to June 13th, which is the day where I transferred all the fish to different tanks, and then cleaned the UAS just because of that, also because the bubbler bar popped off the suction cup so I needed to get in there anyways.

Pretty meager harvest, but I usually let it go longer, so oh well. Did not test. I thought at this point that the tank was empty, but as it turns out, there was still a goby/pistol shrimp pair hiding out, so I continued to feed about 1/2 cube or less every other day.

The result after 18 days of growth was astonishing. But there is a twist to it. Wait for it....wait for it....

Harvest yesterday, July 1st

Weight, squeezed 114g

Another thing that is noteworthy is that this growth is quite different than what I had been getting previously, which was a sort of grainy, compactable growth. This growth was more volumous, meaning that I would squeeze it and it would 'bounce back' rather than staying compressed when I pancaked it between my hands when squeezing, almost like a foam block re-expands after you squeeze it. Very odd.

So what is the twist you ask?

Had to top off the tank so I waited until the next day to test:

Phosphates: 0.88, which is down a whopping 0.05 over the course of a month

Nitrates, tested on API, were definitely above 40 and likely closer to 60.

What is so telling about this? The harvests I was getting over a period of anywhere from 2-3 weeks in the past was pretty consistent, around 80g. This continued for a number of months (about 3). Nitrate and phosphate continued to rise with feeding at half or less than the supposed 'rated' capacity of the system. Even PWCs would not help the scrubber get over the hump.

Now I take away 90% of the bioload and essentially stop feeding the tank, and the growth increases by 50% over the best harvest I have ever had (which was around 80g, comparable to the 6/1/13 harvest) and 3.5 times more than the previous 13 day growth period immediately preceding it. Yet, not a dent made in phosphates, and hardly a dent made in nitrates.

So what exactly is the deal? Is the UAS growing algae just for the sake of growing it? Sure seems like it! Because it sure doesn't seem to be doing much in the way of actual nutrient reduction, which is in line with it's performance on my 120 before I moved it to the 40.

I'm going to just let it grow for a few more weeks and see if this interesting trend of non-filtering growth continues...

This one was slightly skewed, as I had to replace the suction cups in the box, which did not hold because I didn't clean the box before putting them in, so the screen was kind of floating most of the growth period. However, this didn't seem to affect growth.

Keep in mind here - 40B w/UAS and one goby/shrimp pair being fed about 1/4 cube every other day.

Squeezed (for several minutes): 101g

Nitrates have come down slightly over the past 2 weeks from "definitely over 40" to "closer to 40" on API.

Phosphates not significantly affected - a drop from 0.88 to 0.81.

Now, on Tuesday 7/16 I added 9 cleaner clams from saltwaterfish.com. They quickly all buried themselves and I will have to test the water then try to dig them up to make sure they are all still alive, if the test results show a spike. One thing I have noticed in the last few days is a significant amount of hair algae growth on the glass. This tank is lit only by a few Kessil pendants which are probably too far above the tank, so the light level is pretty low in the system, and with no fish picking away at the rocks for a while now, it's starting to show.

-------------------

So now, over to the 120 with the waterfall. This tank is being fed 2 cubes every other day, sometimes more. So roughly 6-8 times the amount of food being fed to the 40B

I had a strange thing happen at the last harvest (July 1st), I had been running the LEDs at 1 hour on / 1 hour off continuously. After 14 days, the algae on one side of the screen had almost completely detached, when I pulled out the screen, the back side was 75% gone and the rest peeled off way too easily. So the screen sort of "rebooted", which meant the nutrients came up a bit from the previous downward trend. Pics

So the screen recovered nicely, but during the first week the screen was pretty dark in color and the holes were not filled in.

Squeezed, 36g

Nitrates jumped a bit, up to the 40 range.

Phosphate jumped from 0.09 to 0.15, which is where it was at about a month or so ago

The change I made after this cleaning was the addition of a light blocker at the slot pipe, because as you can see, there is quite a bit of growth over the slot pipe/screen junction. We'll see if that affects anything.

Been a while since I updated this thread. Will be trying to do so more often. Especially since the mirror thread on the scrubber site got deleted after I was banned. Thanks for limiting the exposure of the truth. That won't be happening here.

Been a while since I updated this thread. Will be trying to do so more often. Especially since the mirror thread on the scrubber site got deleted after I was banned. Thanks for limiting the exposure of the truth. That won't be happening here.

Click to expand...

Personally I think that SM is interested in selling product lately than actually discussing the pros and cons of various scrubbers and their effectiveness.

This made me think a bit.

Could too much light/flow or too fast flow actually not be effective?

I was thinking how some denitrators work. Flow through them is extremely slow so that nitrates in the water going through them is used up.

Eventually all of the tank water goes through it over and over, but at a very slow rate.

Of course, the UAS growing algae but not cutting down on the nitrates etc. may be telling you that there is a source of Nitrate and Phosphate in your tank you have to taken into consideration.

Perhaps you have some rotting something hidden somewhere or a buildup of detritus someplace that acts as a nitrate source.